Fastener



Patented Oct. 10, 1944 FASTENER Daniel A. Brennan, deceased, late of Chicago, 111.,

by Elmer L. Zwickel, executor, Chicago, Ill., assignor to Acco Products, Inc., Long Island City, N. Y., a corporation of New York Original application December 16, 1940, Serial No. 370,372. Divided and this application July 22, 1942, Serial No. 451,845

8 Claims.

This application is a division of application Serial No. 370,372, filed December 16, 1940, which has matured into Patent No. 2,319,438, granted May 18, 1943.

The invention relates to improvements in fasteners for binding papers together, such as letters in a file; and more particularly to a new and improved fastener including a base having spaced prongs at its ends adapted to extend through apertures in the papers, and a compressor adapted to have said prongs bent inwardly from each end down against said compressor and be held in place by sliding latches. The specific struc ture herein disclosed, embodies novel means on the prongs and latches to embracingly co-act to prevent inadvertent shifting of the latches off from the ends of the prongs.

An object of the invention is to provide an improved fastener of the foregoing type with novel means for effecting a yieldable gripping engagement between the prongs and the latches to resist latch displacement after the latter are moved into position to hold the prongs over the compressor.

Another object is to provide an improved fastener of the type described with novel means for effecting a frictional embracing engagement between means on the prongs and latches to resist displacement of the latches after they are moved over into engagement with the prongs in any of their Variable positions on the compressor.

Another object is to provide a fastener of the character described embodying means to provide a bound file of minimum thickness.

Another object is to provide a fastener of the character described which is inexpensive to manufacture, simple to assemble, and easy and positive in operation.

The foregoing and such other objects of the invention as will appear hereinafter as the description proceeds, will be more readily understood from a perusal of the following specification, reference being had to the accompanying drawing; in which:

Fig. 1 is a plan View of an embodiment of the improved fastener.

Fig. 2 is a transverse sectional view taken on line 22 of Fig. 1.

Fig. 3 is a plan View of another embodiment of the invention.

Fig. 4 is a transverse sectional View taken on line 4-4 of Fig. 3.

Paper fasteners of the type comprising a base having spaced prongs adapted to pass through apertures in a stack of papers, and a compressor adapted to receive said prongs bent down thereover, in some instances are provided with latches for sliding over the prongs after the latter are in their bent down position. In such devices, the latches frequently are provided with means to coact with the prongs or means on the prongs to prevent inadvertent sliding of the latches off of the prongs. Such known organizations however are disadvantageous primarily because they relyupon the inherent resiliency of the bent over prong portions to maintain the interlocking relationship.

While such function may be satisfactory in many instances of use it is not infrequent, when the prongs become sufficiently distorted because of repeated use, that the free ends thereof no longer tend to elevate themselves from the compressor face sufficiently to bear against the bottom faces of the overlying latches. Such devices necessarily also require a maximum amount of clearance between the top face of compressor and the bottom face of the sliding latch to permit free flexing vertically of the prong while the latch is being moved into association therewith.

It should be understood that it is of primary importance that the bound file of papers be kept at a minimum thickness to economize on the amount of filing space required therefor. The instant fastener is materially less in its over-all height and embodies all of the desirable characteristics of known types of interlocking latch mechanisms.

The fastener shown in Figs. 1 and 2 comprises a base I I provided on its ends with spaced prongs I2 adapted to extend through similarly spaced openings in a stack of papers (not shown). The prongs I2 preferably are substantially narrower than the body of the base and are struck at right angles thereto. The prongs also preferably are formed with upwardly struck projections l3, adjacent their free ends, for a purpose that will hereinafter appear. The base I I is adapted to be positioned to lie against the bottom of the stack of papers when in position for use.

The compressor l4 consists of a strip of sheet material preferably recessed, at its ends, as at 15, for receiving the extended ends of the prong 12, after said prongs have been passed through the papers, and is adapted to lie against the top of the stack. A pair of spaced guides or tracks l6 are formed on each longitudinal edge of the compressor. These tracks preferably areformed in the shape of ribs 17 spaced inwardly of the free edges thereof to define elevated marginal flanges 18. Upon reference to Fig. 2 it is noted Each latch consists preferably of by folding the free end portions of the latches downwardly and then inwardly to embrace the marginal flanges I8. It should be apparent that the latches l9 are free to slide longitudinally the entire length of the compressor and that their shoe portions 22 are maintained elevated above the bottom plane of the compressor so as not to interfere with or otherwise engage the top sheet of the file of papers.

Each latch has an apertured recess 23 substantially centrally located in its bridge portion,

which recess is connected with one edge of said bridge portion by a slot 24.

In use, the latches are moved from a substantially medial position on the compressor outwardly one over the free end portion of each bent down prong. Such movement carries the slot 24 of a latch into embracing engagement with a prong projection l3 and continued outward movement carries the prong projection [3 into the recessed opening 23 of the latch. It should be apparent that the co-acting engagement, or yieldable gripping by the latch with the prong projection I3, is efiected by a flexing of the latch bridge portion 2| as distinguished from downward flexing movement of the prong as in prior devices. It is, therefore, evident that the depth of the channel defined between guides It need be but the minimum required to permit free sliding of the latch bridge portion over the top face of the bent down prong.

The fastener illustrated in Figs. 3 and 4 is substantially like the embodiment shown in Figs. 1 and 2 and described in detail hereinabove. In this form of construction the compressor plate Ma has longitudinal guide lfia, including ribs Ila and marginal flanges l8a, coextensive with its length defining a longitudinal channel to receive the bent over end portions of the prongs 12a on base H. These ribs are of a highth substantially equal to the thickness of the prong material so that the top surface of the bent over prong portions lie substantially in the plane of the top of the ribs. Latches 19a, having a bridge portion 2m overlying the channel, are formed at their ends with shoe portions 22a arranged to engage beneath the margins IBa of the compressor, and longitudinal sliding of the latches outwardly off the compressor ends and inwardly beyond the compressor center is prevented by stops 25. A downwardly extending fold or IibI 26 in each latch provides a projection to engage in and frictionally co-act with a slot 21 in an underlying prong portion when the latches are moved outwardly thereover so as to thereby retard free movement of the latches off the ends of the prongs. In the instant disclosure, the rib 26 is located on the longitudinal center of the bridge portion and it extends across the entire width of the latch material. The compressor illustrated in this embodiment of the invention is provided with transverse slotted openings 28 to receive the prongs during assembly of the fastener.

The improved fasteners clearly provide means for effectively holding the latches in position on the bent down prong without the usual objectional characteristics of excessive thickness and dependency upon prong resiliency; and it should be apparent that the organization disclosed in the accompanying drawing and described herein may readily embody various modifications in detail structure such as, for example, substitution of the recesses 15 in the Fig. 1 compressor for the slotted openings 28 in the Fig. 3 compressor, or vice versa, without departing from the spirit of the invention or the scope of appended claims.

What is claimed is:

1. A paper fastener comprising, a base having spaced bendable prongs, a compressor having a longitudinal channel in its top face of a depth substantially equal to the thickness of the prongs in which said prongs are adapted to lie when bent inwardly towards each other over the compressor, a projection on the top face of each bent over prong portion, latches slidable on the compressor one over each prong, and resilient means in said latches cooperating with said projections to frictionally retard free sliding of the latches off of said prongs.

movement of the projection into 2. A paper fastener comprising, a base having spaced bendable prongs, a compressor having a longitudinal channel in its top face of a depth substantially equal to the thickness of the prongs in which said prongs are adapted to lie when bent inwardly towards each other over the compressor, a projection on the top face of each bent over prong portion, latchesslidable on the compressor, and a substantially flat bridge portion on each latch each to overlie one of said prongs, said bridgeportions each having a slot extending inwardly from an edge to receive and frictionally embrace the projection on the underlying prong to prevent free sliding of the latches off of said prongs.

3. A paper fastener having, in combination, a base with spaced prongs, a compressor having a longitudinal channel in its top face of a depth substantially equal to the thickness of the prongs into which said prongs are adapted to be bent, latches including substantiallyjjflat bridge portions secured to said compressor and bridging said channel for longitudinal sliding movement one over each prong, a projection on each prong, the bridge portions of said latches each having a hole therein providing a recess to co-act with the respective projections to hold the latches in position over said prongs, and a restricted passageway connecting each recess with one edge of its bridge portion to facilitate and out of its related recess.

4. A paper fastener comprising, a base having spaced bendable prongs, a compressor having a longitudinal channel of a depth substantially .equal to the thickness of the prongs into which said prongs are adapted to be bent, at least one of the prongs having a projection thereon, and a latching member movable on the compressor longitudinally thereof and having a fiat bridge portion extending transversely over said chan- -nel, said bridge portion overlying said one prong and having a slot therein to embracingly and resiliently engage said projection when the latch is located in a predetermined position with respect to said prong.

longitudinal channel in its top face of a depth substantially equal to the thickness of the prongs and into which a portion of at least one prong is adapted to lie when beat down over the face of the compressor, a latching member movable on the compressor longitudinally thereof and having a flat bridge portion extending transversely over the channel to overlie the underlying prong portion, a projection on one of the portions, and the other portion having a slotted opening to frictionally receive and b-indingly embrace the projection to prevent free sliding of the latch oil" of said prong portion.

6. A latch for paper fastener compressors comprising, a substantially rectangular bridge portion for sliding the latch along a compressor, said bridge portion having a medial rib on its bottom face, and shoe portions formed at each end of the bridge portion for slidably supporting the latch on the compressor.

'7. A paper fastener comprising, a base having spaced bendable prongs, a compressor having a longitudinal channel in its top face of a depth substantially ,equal to the thickness of the prongs in which said prongs are adapted to lie when bent inwardly towards each other over the compressor, said bent over prong portion having a slot extending inwardly from its free end, latches slidable on the compressor one over each prong, and a projecton on said latches cooperating with said slots to frictionally retard free sliding of the latches off of said prongs.

8. A paper fastener comprising, a base having spaced bendable prongs, a compressor having a longitudinal channel of a depth substantially equal to the thickness of the prongs into which said prongs are adapted to be bent, at least one of the prongs having a slot extending inwardly from its free end, and a latching member movable on the compressor longitudinally thereof and having a flat bridge portion extending transversely over said channel, said bridge portion overlying said one prong and having a projection on its bottom face to be emb-racingly and resiliently received in the said prong slot when the latch. is located in a predetermined position with respect to said prong.

ELMER L. ZWICKEL, Executor of the Estate of Daniel A. Brennan,

Dec ased. 

